How is ERG mode working?

[puremana]

Firstly, I just want to say that Auuki is awesome and I appreciate all of the work that you dvmarinoff and everyone else have done on it. I have found using it to be a little bit confusing, which is surprising considering how simple it all looks. Most of it, I think I have figured out, but I have some ERG mode questions.

1. What is ERG mode actually doing? If I set ERG to 360 and pedal at 90 cadence, after pedaling for a minute, I would personally expect my power output to be close to 360w. i.e if I pedal for 2 minutes, if the first minute is the ERG adjusting, the second minute should hover above and below 360w and I would expect my second minute average power to be 360w or very close to it.

What happens in practice is that it hovers at around 300w for me. If I need to average 360w, I would need to set the ERG to probably around 420.

Is it factoring in something else instead? Like my FTP? Or Is it my trainer (Elite Direto XR-T Smart Trainer) that is doing this? The ERG mode is definitely working, just doesn't match what I would expect it to match.

2. Another thing I notice is that seemingly randomly when I am on ERG mode it will get much harder for a few seconds, then go back to normal. Keeping with the other example, if I have ERG set to 360, and I am averaging 300w, then without changing any cadence or gears or anything, the resistance will get harder and I will end up doing 350w for a few seconds, and then it will return back to 300w. This happens maybe every 3 minutes, so not very common. Is this my trainer?

Neither of these "issues" happened when I was riding on Zwift

[beamends]

Possibly similar to this: #284